The 33-year-old Mongolian returned to Tokyo late Thursday from the city of Fukuoka, where the 15-day Kyushu grand sumo tournament is underway, apparently to meet with investigators from the Tottori Prefectural Police.

It has been alleged that Harumafuji, who belongs to the Isegahama stable in Tokyo, angrily assaulted Takanoiwa, 27, also a Mongolian wrestler, over his attitude.

They were drinking with other Mongolian wrestlers at a restaurant in the city of Tottori during the night of Oct. 25 when the alleged incident took place.

The wrestlers were visiting Tottori as part of sumo’s annual autumn local tour.

Takanoiwa, who is in the Takanohana stable, was hospitalized from Nov. 5 to 9. He was diagnosed with a skull base fracture and other injuries requiring about two weeks to heal.

The Tottori police are expected to investigate the relationship between the alleged assault and the injuries, the sources said.

The police have already questioned Takanoiwa about the incident, after accepting a victim report on his behalf. They have started questioning the Tottori restaurant staff.

The police will also seek testimony from wrestlers who were at the restaurant, including Hakuho, another grand champion, sources said.

Hakuho has denied reports that Harumafuji used a beer bottle to assault Takanoiwa.

“Harumafuji didn’t use a beer bottle or get on top of (Takanoiwa)” to beat him, Hakuho told reporters Thursday, while confirming that Harumafuji struck Takanoiwa with his bare hand.

Takanoiwa missed the Kyushu tournament from the opening day. Harumafuji dropped out Tuesday, the third day of the competition.